Molded terminal block



Aug. 26, 1958 A. c. DEMURJIAN ,6

MOLDED TERMINAL BLOCK Filed May 11, 1954 2 Sheets-Sheet 1 IN V EN TOR.

ASHOD CHARLES DEMURJIAN ATTO NEY Aug. 26, 1958 Filed May 11, 1954 A. c. DEMURJIANL 2,849,699

MOLDED TERMINAL BLOCK 2 Sheets-Sheet 2 INVENTOR. ASHOD CHARLES DEMURJIAN BY L ATTORNE United States Patent 2,849,699 MOLDED TERMINAL BLOCK Ashod Charles DemurjiamCranston, R. 1. Application May 11, 1954, Serial No. 423,9;1 1 Claim. (Cl. 339-198) My present invention relates to the electrical art and more particularly to a" molded terminalblock.

' The principal object of the present invention is to provide a strip terminal block in which the bus bar Connections are assembledduringthe molding operation thus eliminating subsequent manual assembly operations.

Another object of the present invention is to provide a molded terminal block which does not require additional insulation when mounting on a panel board.

A further object of the present invention is to provide a molded terminal block in which the bus bar strips are anchored in place without the use of screws.

Another object of the present invention is to provide a molded terminal block which requires no further assembly operations after molding.

Another object of the present invention is to provide a molded terminal block which can be put into direct use in a circuit without the necessity of slow hand assemblies.

A further object of the present invention is to provide a molded terminal block which is simple in construction and easy and economical to manufacture and assemble.

With the above and other objects and advantageous features in view, my invention consists of a novel arrangement of parts, more fully disclosed in the detailed description following, in conjunction with the accompanying drawings, and more particularly defined in the appended claim.

In the drawings:

Fig. 1 is a plan view of a molded terminal block embodying my invention.

Fig. 2 is a side elevation thereof.

Fig. 3 is an enlarged section taken on line 33 on Fig. 1.

Fig. 4 is a section taken on line 4-4 on Fig. 3.

Fig. 5 is an enlarged perspective view of the bus bar insert.

Fig. 6 is a plan view of an alternate form of terminal block.

Fig. 7 is a side elevation thereof.

Fig. 8 is an enlarged section taken on line 8-8 on Fig. 6.

Fig. 9 is a section taken on line 99 on Fig. 8.

Fig. 10 is an enlarged perspective view of the bus bar insert.

In complicated electric and electronic circuits the voltage will vary to different parts of the circuit. This applies to instruments such as electronic brains and other types of computing machines. In distributing the current, a molded terminal block is provided in the form of an elongated strip of molded dielectric material having a plurality of connecting bus bars separated by integral barriers to prevent arcing. A particular voltage line is connected to one end of a bus bar and the lead connected to the other end. In the conventional form each bus bar is locked to the block by a central screw or bolt extending through an opening in the rear. As a result, when the terminal block is mounted on a panel board, a strip of insulating material must be placed behind it to prevent arcing. The terminal blocks are molded in plastic and sold to the electrical manufacturer .who then must assemble the block with the bus bars. It has been found that the labor involved during this assembly is much more than the cost of the block and takes a considerable amount of time.

The present invention is designed to provide a molded terminal block which requires no assembly and no separate insulating strip. This is accomplished by so designing the block and the bus bar that the bus bar can be anchored to the block during the molding operation. This eliminates the bolt openings and provides the block with a solid dielectric back which can be mounted directly on a panel board. The time consuming and costly manual assembly operations are completely eli minated.

Referring more in detail to the drawings illustrating my invention, Figs. 1 to 5 inclusive illustrate one form of terminal block embodying my invention. In this form the block base 10 is molded in an elongated rectangular strip having a plurality of spaced integral barriers 11 extending transversely across the top in parallel relation. For diiferent requirements the base 10 may be made in varying widths and lengths. To insure proper insulation the base will range from /8" to /2 thick and each barrier 11 is approximately A" thick and a A" in height.

In some installations several leads may be taken from a single voltage line. In such cases one or more of the barriers 11 can be eliminated and the bus bar at that point can be of multiple Width. For example, in the form shown in Fig. 1, one of the barriers 11 has been eliminated adjacent the left end to form a portion 12 having approximately three times the width of the normal spacing between the bus bars.

Referring to Fig. 5, each bus bar comprises a rectangular metal plate 13 of the length and width to fit into the space between the barriers 11. Each plate 13 is provided adjacent each end with an integral depending rectangular portion 14. A threaded opening 15 extends through the plate 13 into each portion 14. This is designed to hold the binding posts to which the electrical connections are made at each end of the bus bar.

In molding the terminal block, it is essential that the bus bars 13 become firmly anchored in the base 10. Each bus bar 13 is therefore stamped, drawn, or die cast so that each portion 14 is slightly wider at the bottom end than at the top. For example, to provide the proper threaded opening 15, the upper end of the portions 14 should be in width and the lower end should be in width. Thus, when the bus bars 13 are positioned in the mold and molded into the base 14) they will become firmly anchored as shown in Figs. 3 and 4 and cannot thereafter be removed or fall out. The wider lower end of the portions 14 lock the bus bar in place.

With the above construction the assembly operation takes place in the mold and the completed item is thus delivered ready for use.

In the form shown in Figs. 6 to 10 inclusive a different type of anchoring means is provided for holding the bus bar in the molded strip. In this form the base 16 is provided with the integral barriers 17 identical with the form shown in Fig. 1. Here again a barrier can be omitted to form a wider section 18. However, in this form the bus bar, shown in Fig. 10 comprises a flat plate 19 of slightly greater thickness than the plate 13 used in Fig. 1. The end portions of the plate 19 are of sufficient width, as at 20 to fit between adjacent barriers. However, the body portion is provided along each side edge with lateral extensions 21 which are adapted to extend into the lower portion of each barrier 17 as shown in Fig. 8 and in dotted lines in Fig. 1.

Each bus bar 19 is provided with assembly openings 22 and during the molding operation insert pins may be provided to extend these openings into the base 16 as at 23. After the molding operation the openings 22 must be threaded. This form therefore requires a separate threading operation.

I have thus provided a molded terminal block in which the bus bar connections are molded into the block to become permanently anchored therein. The back of the block is therefore solid and requires no further insulation. Virtually all of the manual assembly Work has been eliminated. In the bolted form vibrations tend to loo-sen the bus bars. In the present invention the bus bars cannot be loosened or removed.

The molded terminal block of the present invention is therefore much more economical to manufacture and assemble and results in a much better product. Other advantages of the present invention will be readily apparent to a person skilled in the art.

I claim:

A molded terminal block comprising a base of molded dielectric material in the form of an elongated rectangular block, a plurality of integral rectangular barrier strips extending transversely across the top of said base in spaced parallel relation, a plurality of conducting bus bar plates mounted on said base between said barrier strips and extending transversely across the width of said base, said plates each having a threaded opening adjacent each end, and means integral with said plates for anchoring said plates to said base, said means including integral rectangular blocks extending downwardly adjacent each end of said plates beneath the plate openings and extending into said base, said threaded openings extending into said blocks, the lower end of each block being wider than the upper end in a direction parallel to said plate.

References Cited in the file of this patent UNITED STATES PATENTS 464,368 Kimble Dec. 1, 1891 1,517,017 Roth Nov. 25, 1924 1,693,303 Mackintosh Nov. 27, 1928 2,509,701 Smith May 30, 1950 2,671,888 Hadden et al. Mar. 9, 1954 FOREIGN PATENTS 872,070 France Jan. 29, 1942 

